PDDs are a class of disorders defined by both American and International diagnostic systems (Le, the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) and World Health Organization: International Classification of Diseases, Tenth revision (ICD-10)). The spectrum of PDDs include disorders such as Autism, Aspergers, ADD, and ADHD. PDDs are typically characterized by multiple distortions in the development of basic psychological functions that are involved in the development of social skills and language, such as attention, perception reality testing and motor movement. In addition, many children diagnosed with autism, for example, suffer from primary diffuse gastrointestinal problems such as protracted diarrhea and constipation. Although PDDs are currently of unknown etiology, many conventional methods, such as dietary alteration, behavioral modification, and medication, have been utilized for treating individuals suffering from PDD related disorders. Unfortunately, PDD related disorders have no known treatment beyond that which is symptomatic, and these conventional methods have proven unsuccessful in allowing such children and adults to become symptom, or disorder free.
A child which displays signs of developmentally inappropriate inattention, impulsivity and hyperactivity is typically diagnosed as having ADD and/or ADHD. With these disorders, there can be marked disturbances of organization, distractibility, impulsivity, restlessness, and other disturbances of language and/or social behavior. A combination of psychiatric care and medicine is typically used for treating children with ADD and ADHD.
It was recently discovered that the administration of secretin, a gastrointestinal peptide hormone, to children diagnosed with autism resulted in ameliorating the symptoms associated with autism. This finding was published in the article by Horvath et al., entitled Improved Social and Language Skills After Secretin Administration In Patients with Autistic Spectrum Disorders, Journal of the Association for Academic Minority Physician Vol. 9 No. 1, pp. 9-15, January, 1998. The secretin administration, as described in Horvath, was performed as a diagnostic procedure, i.e., to stimulate pancreaticaobiliary secretion during an upper gastrointestinal endoscopy, rather than as a therapeutic procedure. Although the specific mechanism by which the secretin improved the autistic-related symptoms was not specifically identified, Horvath postulated that secretin may have had a direct or indirect effect on the central nervous system. What is important, however, is that this was the first time that gastrointestinal problems of autistic children were linked to a possible etiology in autism.
Accordingly, in view of such findings, a method for determining whether an individual suffering from a disorder in the PDD spectrum will benefit from the administration of secretin, other neuropeptides, peptides and/or digestive enzymes, as well as a therapeutic method for treating such individuals with the administration of secretin, other neuropeptides, peptides and/or digestive enzymes, are highly desired.